RU2480596C2 - Conversion mechanism of piston back-and-forth movement to rotational movement with rack-and-pinion mechanism in internal combustion engine - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: conversion mechanism of piston back-and-forth movement to rotational movement with a rack-and-pinion mechanism in the internal combustion engine consists of a cylinder block, a piston, a piston pin and a piston-rod. Two toothed rims are installed on the engine shafts under each cylinder. Piston with piston-rod and two toothed racks installed on opposite sides relative to the engine shaft moves along the cylinder axis. Toothed racks are constantly engaged with two toothed rims on the engine shaft with similar number of teeth at the angle of 180° and at movement of the piston-rod with the piston, toothed rims rotate opposite each other. At dead points of the piston, one toothed rim is disengaged from the engine shaft and rotates idly, and at the same time, the second toothed rim is engaged with the engine shaft, thus transmitting to it the rotational movement in the same direction. The piston stroke is restricted with a limit stop on the toothed rim and a limit stop on the toothed rack.

EFFECT: reduction of mechanical losses.

9 dwg, 1 tbl

Description

The invention relates to internal combustion engines, and more specifically, serves to replace the crank mechanism by a mechanism for converting the reciprocating motion of the piston into the rotational movement of the output shaft of the engine with two rack and pinion gears.

It is known that on modern internal combustion engines, a crank mechanism is used to convert the reciprocating motion of the piston into rotational motion of the shaft. During the expansion stroke, the force from the gas pressure is transmitted through the piston and the piston pin to the connecting rod and at the same time the lateral force presses the piston against the cylinder wall. The force directed along the connecting rod axis acts on the crankshaft through the connecting rod neck, which decomposes into a radial force directed along the radius of the crank and pressing the crankshaft main necks to the bearings, and a tangential tangential force directed perpendicular to the radius of the crank applied to the connecting rod neck and crankshaft. In the crank mechanism, one of the main parameters affecting the amount of transmitted power from the gas pressure in the cylinder to the piston is the angle of rotation of the crankshaft, the movement of the piston and the angle of deviation of the connecting rod from the cylinder axis. During the working stroke of the piston, the crankshaft rotates through an angle from 0 to 180 °. The torque on the engine shaft, which depends on the tangential tangential force, increases from 0 to maximum when the crankshaft rotates from 0 to 90 °, and decreases to 0 when further turns from 90 to 180 °. The heat energy developed inside the cylinder by pressure gases on the piston is converted into mechanical work, part of this mechanical energy is spent on overcoming useful resistances, i.e. to rotate the crankshaft and drive consumers. The rest of the mechanical energy is spent on overcoming internal resistance in the engine (friction between the piston and the cylinder liner, friction of the crankshaft journals in bearings, etc.). Part of the mechanical energy is spent on increasing the strength of the moving parts of the mechanism, mainly the flywheel. The flywheel is a battery of kinetic energy for the purpose of its return to the output of the pistons from the dead points, facilitates the rotation of the crankshaft when starting the engine and its uniform rotation. The larger the size of the flywheel and the cycle frequency of the engine, the smaller the variation in angular velocity.

The design of the crank mechanism is a complex device that requires high precision in the manufacture and care during operation. The design of the crank mechanism is described in detail in the literature [Margulis Yu.B. Internal combustion engines. Theory, construction and calculation. Ed. 2nd. M .: Engineering, 1972, p.14, p.97, p.256-296; Shestopalov K.S., Demikhovsky S.F. Cars. - M .: DOSAAF, 1989, p.12-24].

The aim of the present invention is to eliminate these drawbacks and improve the technical and economic performance of the engine by reducing mechanical losses, eliminating fluctuations in angular velocity (respectively, reducing the number of engine revolutions) and simplifying the design.

This goal is achieved by the fact that, in contrast to the known internal combustion engine, consisting of a cylinder block, piston, piston pin, connecting rod and crankshaft, the proposed engine does not have a crankshaft, and the force from the gas pressure on the piston and on the rotation of the engine shaft is transmitted by two gears. On the lateral sides of the connecting rod, on the opposite sides of the engine shaft, two gear racks are installed that move with the connecting rod along the axis of the cylinder and are constantly engaged with two gear crowns on the engine shaft with the same number of teeth at an angle of 180 °. When moving the piston with the connecting rod, the ring gears rotate towards each other, and at the dead points of the piston, at the same time, one ring gear disengages from the engine shaft and rotates idle, and the second ring gear engages with the engine shaft, transmitting rotational motion to it. The piston stroke is limited by stops on the ring gear and on the rack. A common keyway is made on the motor shaft for two gear rims with a recess in cross section under the axis of the swinging key. The keyways in pairs (under the first and fourth, second and third cylinders) are located on the same axis and are offset by 180 ° relative to each other. The key for two gear crowns is made by one piece with the axis of the support and rotation in the center, and its shoulders are located at an angle to each other. The height of the dowel is equal to the depth of the groove on the motor shaft, and its shoulders protrude beyond the gears on the crowns and serve as a support for switching the clutch of the gear ring with the motor shaft from a spring-loaded bar sliding on the cam. In the upper (lower) dead points of the piston, the keyways on the motor shaft and on the gear rims are simultaneously aligned in the same plane and the spring loaded with the force of the spring bar is recessed into the keyway on the motor shaft, disengaging the previously engaged gear ring and the second key arm is engaged the keyway on the second gear ring and engages it with the motor shaft.

Figure 1 shows a General view of the conversion mechanism in a longitudinal section of a cylinder block of the engine, with a cutout for better visualization of the structure. Figure 2 shows a view of the mechanism from below with a cutout along the axis of the motor shaft for clarity of interaction between the gear racks, gear crowns and spring-loaded slats with the motor shaft. Figure 3 shows a cross-section of the mechanism, where the shoulder of the swiveling key, the ring gear is engaged with the motor shaft. Figure 4 shows a cross section of the mechanism, where the shoulder of the tread key is recessed in the keyway of the motor shaft, the ring gear on the motor shaft rotates idle. Figure 5 shows the position of the spring-loaded bar, where the ring gear is engaged with the motor shaft. Figure 6 shows the position of the spring-loaded bar, where the shoulder of the swinging key is recessed into the groove of the motor shaft and the ring gear is disengaged from the motor shaft. 7 shows a section along the axis of movement of the connecting rod along the guide sleeve on the motor shaft. On Fig shows the shape of the swinging keys in a side view in the keyway on the motor shaft in an enlarged scale for clarity. Figure 9 shows the position of the shoulder of the swinging key with entry chamfers, recessed into the groove of the motor shaft and the shape of the groove in the ring gear on an enlarged scale.

The reciprocating movement conversion mechanism is located in the crankcase 1 of the cylinder block. In the transverse partitions of the crankcase there are split bearings 2 for bearings 3, which are mounted by spring-loaded rings 5 on the shaft of the engine 4 from axial movement 5. On the shaft of the engine under each cylinder are 2 toothed rings 6 and 7, which alternately engage with the shaft of the motor with a swinging key 8 , and with gear racks 9 and 10 are in constant gearing. Gear racks are located on the connecting rod 11 on different sides relative to the motor shaft. The tail end of the connecting rod 11 with a rectangular profile and an oblong fork-shaped groove along the axis slides along the guide sleeve 12 on the motor shaft, and the lateral surfaces between the end surface on the ring gears 6 and 7. In the tail end, the ends of the connecting rod 11 are fastened by a bar 13. On the end part cams 14 and 15 protrude gear crowns 6 and 7, along which spring-loaded strips 16 and 17 slide, from the force of which the clutch with the motor shaft is transmitted from one to the upper and lower dead points of the piston by the swinging key 8 with input chamfers ring gear on the other. Washers 18 are mounted on the motor shaft between the cams and the spring-loaded rings 5. The gear crowns should rotate freely without jamming on the recessed shoulder of the key 8. On the gear crowns 6 and 7, there is a stop 19, which abuts against the end protrusion 20, symmetrically with respect to the axis and the keyway at the ends of the gear racks 9 and 10 at the extreme upper and lower dead points of the piston 21. On the cams 14 and 15 perpendicular to the axis of the gear ring, the flats are removed above the keyway. The spring-loaded strips 16 and 17 slide along the rails on the brackets 22 and 23, which are mounted in the releasable socket 2. The strips 16 and 17 slide on the surface of the cams 14 and 15, and in the area of the removed flat on the cams from the spring force 24, the shoulder of the swinging key is recessed in a groove on the motor shaft. The gas pressure on the piston 21 is transmitted through the piston pin 25 to the upper head of the connecting rod 11.

The operation of the mechanism for converting the reciprocating motion of the piston to the rotation of the engine shaft by two rack and pinion gears is described on the example of a four-stroke engine with the operation order of cylinders 1-3-4-2, adopted by most engines in which the pistons with the connecting rods are paired (the first with the fourth and the second with a grate) make a reciprocating motion. At the extreme upper and lower points of the piston, the gear ring which was previously engaged in engagement is disengaged, and the second gear ring is engaged with the engine shaft. The operation procedure of the mechanism is shown in the table.

Table 1. The operating procedure of the rack-and-pinion mechanism in a four-cylinder engine and the sequence of switching on the gears 6 and 7 with the engine shaft. angle
rotate
that shaft cylinders one 2 3 four 0-180 slave move release compression inlet 6 7 6 7 6 7 6 7 incl. off off incl. off incl. incl. off 180-360 release inlet slave move compression 6 7 6 7 6 7 6 7 off incl. incl. off incl. off off incl. 360-540 inlet compression release slave move 6 7 6 7 6 7 6 7 incl. off off incl. off incl. incl. off 540-720 compression slave move inlet release 6 7 6 7 6 7 6 7 off incl. incl. off incl. off off incl.

We will consider the operation of the mechanism using an example of the sequence of engagement of gear rims with the engine shaft in tact of the stroke in the first cylinder when the piston is at top dead center:

the ring gear 6 is engaged with the shaft of the engine 4 by the swinging key 8 and the gear rack 9, and the ring gear 7 rotates idle on the shaft of the engine (the key 8 is recessed into the groove of the shaft of the engine). In step with the stroke in the first cylinder, the gas pressure force is transmitted to the piston 21 through the piston pin 25, the connecting rod 11, the gear rack 9, the ring gear 6, the key 8 to rotate the motor shaft 4, creating a torque on it. The ring gear 7 rotates idle on the motor shaft in the opposite direction, while the shoulder of the key 8 is recessed in the keyway of the motor shaft 4 and the outer surface slides along the inner surface of the ring gear 7, and the bar 17 slides on the cam 15 and compresses the spring 24. In the lower the dead point of the piston, the stop 19 on the gear ring 6 abuts against the end protrusion 20 on the gear rack 9, as shown in FIG. 3, and the stop 19 on the gear ring 7 rests on the end protrusion 20 on the gear rack 10, as shown in FIG. 4, while keyways on the memory the crown rings 6 and 7 and the keyway on the shaft of the engine 4 are aligned in the same plane. Due to the force of the spring bar 16, the shoulder of the key 8 is recessed into the key groove on the motor shaft 4, disengaging the ring gear 6 from the motor shaft, and the second shoulder of the key 8 will mesh the ring gear 7 with the motor shaft 4. Entrance chamfers on the keys 8 and the keyway profile in the shape of a trapezoid on the gears 6 and 7 allows for self-centering of the gears relative to the gear racks, to increase the switching time of the engagement of the gears with the motor shaft and, accordingly, increase the number of revolutions gatel. The dynamic impacts of the stops 19 on the gears 6 and 7 and the protrusions 20 at the ends of the gear racks 9 and 10 are compensated by the compression forces of the working mixture in other cylinders (in our case, in the grated cylinder). So the working stroke in the first cylinder ends: the piston 21 will move from the top to the bottom dead center, and the shaft of the engine 4 will make a half turn from 0 ° to 180 °. In the fourth cylinder, the piston moved to the bottom dead center in the “intake” cycle, in the second and third cylinders the pistons moved to the top dead center, respectively, the “release” and “compression” cycles were made. Under each cylinder, the spring-loaded bars 16 or 17 changed the engagement of the gears 6 and 7 with the shaft of the engine 4, the swinging key 8. At an angle of 180 ° -360 ° from the working stroke in the third cylinder (see table), the piston 21 moves down and through the piston finger 25, connecting rod 11, gear rack 9, ring gear 6, key 8, the shaft of engine 4 continues to rotate in the same direction, and in the first cylinder, ring gear 7 rotates in the opposite direction. When the shaft rotates, the ring gear 7 in the first cylinder moves the rack 10 together with the connecting rod 11, the piston pin 25 and the piston 21 to the top dead center. At the top dead center of the piston, the stop 19 on the ring gear 7 abuts against the end protrusion 20 on the gear rack 10, and the stop 19 on the ring gear 6 abuts against the end protrusion 20 on the rack 9, while the keyways on the ring gears 6 and 7 and the keyway the groove on the shaft of the motor 4 are aligned in one plane. Under the force of the spring bar 17, the shoulder of the key 8 is recessed into the key groove on the motor shaft 4, disengaging the gear ring 7 from the motor shaft, as shown in FIG. 4, and the second shoulder of the key 8 will mesh the gear ring 6 with the motor shaft 4 The piston 21 and the reciprocating movement conversion mechanism are returned to their original position and the engine shaft is rotated 360 °. The next two half-turns (360 ° -540 ° and 540 ° -720 °) of the engine shaft will occur from the working stroke in the fourth and second cylinders in a sequence similar to that described above, with the order of operation of the mechanisms indicated in the table.

Using the mechanism for converting the reciprocating motion of the piston to the rotation of the engine shaft with two rack and pinion gears during the expansion stroke, the gas pressure force is transmitted along the cylinder axis and is directed tangentially to the engine shaft gear, giving it a rotational movement, which minimizes mechanical energy losses due to the lack of pressure of the piston against the walls of the cylinder, the absence of radial forces directed along the radius of the crank, and due to the elimination of power losses, oznayuschie from the influence of the angle of rotation of the crankshaft and from the angle of deviation of the connecting rod from the axis of the cylinder. The absence in the rack-and-pinion mechanism of an expensive crankshaft and spliced parts simplifies the design of the engine.

Claims (1)

The mechanism for converting the reciprocating motion of the piston into a rotary rack and pinion gear in an internal combustion engine, consisting of a cylinder block, a piston, a piston pin and a connecting rod, characterized in that two gear rings are installed on the engine shaft under each cylinder, and a piston with a connecting rod and two gear racks mounted on opposite sides relative to the engine shaft, makes a movement along the axis of the cylinder, and gear racks are constantly engaged with two gear rims on the shaft engine with the same number of teeth at an angle of 180 ° and when moving the connecting rod with the piston, the ring gears rotate towards each other, and at the dead points of the piston at the same time one ring gear disengages from the engine shaft and rotates idle, and the second ring gear engages with the shaft engine, transmitting rotational motion to it in the same direction, while the piston stroke is limited by focus on the ring gear and focus on the gear rack.

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